At 31 years of age, Chelsea will bring a fresh voice to the board room — and the perspective of someone much closer to the desired audience for IAC's products than, say, Diller.

While there are many people in their early thirties who can boast of broader or deeper business experience, few people her age are as comfortable around very wealthy and powerful people. If Diller wants a young person who can hold her own against older, more experienced business people, Chelsea is a great choice.

A good corporate board should be characterized by constant tension, with non-executive directors respectfully questioning the decisions of management. This can make board meetings very uncomfortable, especially for young people. Chelsea's background makes her very well suited to dealing with this situation.